*heading
*preprint, model=yes
*node,nset=all
 11,
 12,1.
 13,1.,1.,
 14,0.,1.,
 15,0.,0.,1.
 16,1.,0.,1.
 17,1.,1.,1.
 18,0.,1.,1.
*nset,nset=face11
 11,12,13,14
*nset,nset=face12
 15,16,17,18
*nset,nset=face13
 11,12,15,16
*nset,nset=face14
 13,16,17
*nset,nset=face15
 13,14,17,18
*nset,nset=face16
 14,11,18,15
*nset, nset=ndisp1
 12
*nset, nset=ngrp1
 11,13,14
*element,type=c3d8r,elset=c3d
 1,11,12,13,14,15,16,17,18
**
*elset, elset=eall
 c3d
*solid section,elset=eall,material=low_density_foam
 1.0,
*material,name=low_density_foam
*density
 5.0000e-010,
***hyperfoam, n=3
**-1048.43,0.3025,532.20,0.3958,517.027,0.2135,0.2,0.2,
**0.2
**
** Use equivalent N=4 definition for QA purposes
**
*hyperfoam, n=4
-1048.43,0.3025,532.20,0.3958,517.027,0.2135,0.0,1.0, 
0.2,0.2,0.2,0.0
**
*mullins effect
1.75, 0.3, 0.6
*viscoelastic,time=prony
0.5,0.5,3.e-3
*equation
 2,
 face14,1,1,ndisp1,1,-1
*equation
 2,
 ngrp1,3,1,ndisp1,3,-1
*nset, nset=ndisp
 ndisp1
*boundary,type=velocity
 face12,3
 face13,2
 face16,1
*step
 biaxial loading
*dynamic,explicit
 ,1.0e-2
*boundary, type=velocity
 ndisp,1,1,0.5e2
 ndisp,3,3,-0.5e2
*output,field
*element output
 s, le
*node out
 rf, u
*output, history, variable=preselect
*element output, elset=eall
 s11, le11, ne11, ener
*node out, nset=ndisp
 rf1,rf3
*end step
*step
 unloading
*dynamic,explicit
 ,1.0e-2
*boundary, type=velocity
 ndisp,1,1,-0.5e2
 ndisp,3,3,0.5e2
*end step
*step
 biaxial loading
*dynamic,explicit
 ,1.0e-2
*boundary, type=velocity
 ndisp,1,1,1.0e2
 ndisp,3,3,-1.0e2
*end step
*step
 unloading
*dynamic,explicit
 ,1.0e-2
*boundary,type=velocity
 ndisp,1,1,-1.0e2
 ndisp,3,3,1.0e2
*end step